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ZnI2 + Mg(OH)2 → MgI2 + Zn(OH)2

ZnI₂ + Mg(OH)₂ → MgI₂ + Zn(OH)₂

Last updated: June 13, 2022

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Zinc iodide + Mg(OH)₂Magnesium hydroxide
⟶
MgI₂Magnesium iodide + Zn(OH)₂Zinc hydroxide

The reaction of zinc iodide and magnesium hydroxide yields magnesium iodide and zinc hydroxide. This reaction is an acid-base reaction and is classified as follows:

Reaction of salt of weak base and strong base

Table of contents

Reaction data

Reactants

Chemical formula	Name	Coefficient	Type	Type in general equation
ZnI₂	Zinc iodide	1	Brønsted acid	Salt of weak base
Mg(OH)₂	Magnesium hydroxide	1	Brønsted base	Strong base

Products

Chemical formula	Name	Coefficient	Type	Type in general equation
MgI₂	Magnesium iodide	1	Conjugate acid	Salt of strong base
Zn(OH)₂	Zinc hydroxide	1	Conjugate base	Weak base

Thermodynamic changes

Changes in standard condition (1)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG 130.5 kJ/mol K 0.14 × 10⁻²² pK 22.86: ZnI₂Crystalline solid + Mg(OH)₂Crystalline solid
⟶
MgI₂Crystalline solid + Zn(OH)₂Crystalline solidγ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	130.5	–	–
per 1 mol of Zinc iodide	–	130.5	–	–
per 1 mol of Magnesium hydroxide	–	130.5	–	–
per 1 mol of Magnesium iodide	–	130.5	–	–
per 1 mol of Zinc hydroxide	–	130.5	–	–

Changes in standard condition (2)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG 130.7 kJ/mol K 0.13 × 10⁻²² pK 22.90: ZnI₂Crystalline solid + Mg(OH)₂Crystalline solid
⟶
MgI₂Crystalline solid + Zn(OH)₂Crystalline solidβ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	126.7	130.7	−13.4	–
per 1 mol of Zinc iodide	126.7	130.7	−13.4	–
per 1 mol of Magnesium hydroxide	126.7	130.7	−13.4	–
per 1 mol of Magnesium iodide	126.7	130.7	−13.4	–
per 1 mol of Zinc hydroxide	126.7	130.7	−13.4	–

Changes in standard condition (3)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG 129.2 kJ/mol K 0.23 × 10⁻²² pK 22.63: ZnI₂Crystalline solid + Mg(OH)₂Crystalline solid
⟶
MgI₂Crystalline solid + Zn(OH)₂Crystalline solidε

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	125.3	129.2	−13.0	–
per 1 mol of Zinc iodide	125.3	129.2	−13.0	–
per 1 mol of Magnesium hydroxide	125.3	129.2	−13.0	–
per 1 mol of Magnesium iodide	125.3	129.2	−13.0	–
per 1 mol of Zinc hydroxide	125.3	129.2	−13.0	–

Changes in standard condition (4)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Crystalline solid + Mg(OH)₂Crystalline solid
⟶
MgI₂Crystalline solid + Zn(OH)₂Crystalline solidprecipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	126.4	–	–	–
per 1 mol of Zinc iodide	126.4	–	–	–
per 1 mol of Magnesium hydroxide	126.4	–	–	–
per 1 mol of Magnesium iodide	126.4	–	–	–
per 1 mol of Zinc hydroxide	126.4	–	–	–

Changes in standard condition (5)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Crystalline solid + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Crystalline solid + Zn(OH)₂Crystalline solidγ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Changes in standard condition (6)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Crystalline solid + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Crystalline solid + Zn(OH)₂Crystalline solidβ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	122.6	–	–	–
per 1 mol of Zinc iodide	122.6	–	–	–
per 1 mol of Magnesium hydroxide	122.6	–	–	–
per 1 mol of Magnesium iodide	122.6	–	–	–
per 1 mol of Zinc hydroxide	122.6	–	–	–

Changes in standard condition (7)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Crystalline solid + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Crystalline solid + Zn(OH)₂Crystalline solidε

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	121.3	–	–	–
per 1 mol of Zinc iodide	121.3	–	–	–
per 1 mol of Magnesium hydroxide	121.3	–	–	–
per 1 mol of Magnesium iodide	121.3	–	–	–
per 1 mol of Zinc hydroxide	121.3	–	–	–

Changes in standard condition (8)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Crystalline solid + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Crystalline solid + Zn(OH)₂Crystalline solidprecipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	122.3	–	–	–
per 1 mol of Zinc iodide	122.3	–	–	–
per 1 mol of Magnesium hydroxide	122.3	–	–	–
per 1 mol of Magnesium iodide	122.3	–	–	–
per 1 mol of Zinc hydroxide	122.3	–	–	–

Changes in aqueous solution (1)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG 2.9 kJ/mol K 0.31 × 10⁰ pK 0.51: ZnI₂Ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Un-ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	2.9	–	–
per 1 mol of Zinc iodide	–	2.9	–	–
per 1 mol of Magnesium hydroxide	–	2.9	–	–
per 1 mol of Magnesium iodide	–	2.9	–	–
per 1 mol of Zinc hydroxide	–	2.9	–	–

Changes in aqueous solution (2)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG −28.2 kJ/mol K 8.72 × 10⁴ pK −4.94: ZnI₂Ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidγ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	−28.2	–	–
per 1 mol of Zinc iodide	–	−28.2	–	–
per 1 mol of Magnesium hydroxide	–	−28.2	–	–
per 1 mol of Magnesium iodide	–	−28.2	–	–
per 1 mol of Zinc hydroxide	–	−28.2	–	–

Changes in aqueous solution (3)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG −27.9 kJ/mol K 7.72 × 10⁴ pK −4.89: ZnI₂Ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidβ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	−30.33	−27.9	−8.0	–
per 1 mol of Zinc iodide	−30.33	−27.9	−8.0	–
per 1 mol of Magnesium hydroxide	−30.33	−27.9	−8.0	–
per 1 mol of Magnesium iodide	−30.33	−27.9	−8.0	–
per 1 mol of Zinc hydroxide	−30.33	−27.9	−8.0	–

Changes in aqueous solution (4)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG −29.5 kJ/mol K 1.47 × 10⁵ pK −5.17: ZnI₂Ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidε

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	−31.67	−29.5	−7.6	–
per 1 mol of Zinc iodide	−31.67	−29.5	−7.6	–
per 1 mol of Magnesium hydroxide	−31.67	−29.5	−7.6	–
per 1 mol of Magnesium iodide	−31.67	−29.5	−7.6	–
per 1 mol of Zinc hydroxide	−31.67	−29.5	−7.6	–

Changes in aqueous solution (5)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidprecipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	−30.6	–	–	–
per 1 mol of Zinc iodide	−30.6	–	–	–
per 1 mol of Magnesium hydroxide	−30.6	–	–	–
per 1 mol of Magnesium iodide	−30.6	–	–	–
per 1 mol of Zinc hydroxide	−30.6	–	–	–

Changes in aqueous solution (6)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Un-ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Changes in aqueous solution (7)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidγ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Changes in aqueous solution (8)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidβ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	−34.4	–	–	–
per 1 mol of Zinc iodide	−34.4	–	–	–
per 1 mol of Magnesium hydroxide	−34.4	–	–	–
per 1 mol of Magnesium iodide	−34.4	–	–	–
per 1 mol of Zinc hydroxide	−34.4	–	–	–

Changes in aqueous solution (9)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidε

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	−35.7	–	–	–
per 1 mol of Zinc iodide	−35.7	–	–	–
per 1 mol of Magnesium hydroxide	−35.7	–	–	–
per 1 mol of Magnesium iodide	−35.7	–	–	–
per 1 mol of Zinc hydroxide	−35.7	–	–	–

Changes in aqueous solution (10)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidprecipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	−34.7	–	–	–
per 1 mol of Zinc iodide	−34.7	–	–	–
per 1 mol of Magnesium hydroxide	−34.7	–	–	–
per 1 mol of Magnesium iodide	−34.7	–	–	–
per 1 mol of Zinc hydroxide	−34.7	–	–	–

Changes in aqueous solution (11)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG −6.7 kJ/mol K 1.49 × 10¹ pK −1.17: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Un-ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	−6.7	–	–
per 1 mol of Zinc iodide	–	−6.7	–	–
per 1 mol of Magnesium hydroxide	–	−6.7	–	–
per 1 mol of Magnesium iodide	–	−6.7	–	–
per 1 mol of Zinc hydroxide	–	−6.7	–	–

Changes in aqueous solution (12)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG −37.8 kJ/mol K 4.19 × 10⁶ pK −6.62: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidγ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	−37.8	–	–
per 1 mol of Zinc iodide	–	−37.8	–	–
per 1 mol of Magnesium hydroxide	–	−37.8	–	–
per 1 mol of Magnesium iodide	–	−37.8	–	–
per 1 mol of Zinc hydroxide	–	−37.8	–	–

Changes in aqueous solution (13)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG −37.5 kJ/mol K 3.71 × 10⁶ pK −6.57: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidβ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	−37.5	–	–
per 1 mol of Zinc iodide	–	−37.5	–	–
per 1 mol of Magnesium hydroxide	–	−37.5	–	–
per 1 mol of Magnesium iodide	–	−37.5	–	–
per 1 mol of Zinc hydroxide	–	−37.5	–	–

Changes in aqueous solution (14)

Reaction of zinc iodide and magnesium hydroxide ◆ Δ_rG −39.1 kJ/mol K 7.08 × 10⁶ pK −6.85: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidε

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	−39.1	–	–
per 1 mol of Zinc iodide	–	−39.1	–	–
per 1 mol of Magnesium hydroxide	–	−39.1	–	–
per 1 mol of Magnesium iodide	–	−39.1	–	–
per 1 mol of Zinc hydroxide	–	−39.1	–	–

Changes in aqueous solution (15)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Crystalline solid
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidprecipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Changes in aqueous solution (16)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Un-ionized aqueous solution

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Changes in aqueous solution (17)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidγ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Changes in aqueous solution (18)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidβ

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Changes in aqueous solution (19)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidε

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Changes in aqueous solution (20)

Reaction of zinc iodide and magnesium hydroxide: ZnI₂Un-ionized aqueous solution + Mg(OH)₂Amorphous solidprecipitated
⟶
MgI₂Ionized aqueous solution + Zn(OH)₂Crystalline solidprecipitated

	Standard enthalpy of reaction Δ_rH° kJ · mol⁻¹	Standard Gibbs energy of reaction Δ_rG° kJ · mol⁻¹	Standard entropy of reaction Δ_rS° J · K⁻¹ · mol⁻¹	Standard heat capacity of reaction at constant pressure Δ_rC_p° J · K⁻¹ · mol⁻¹
per 1 mol of Equation	–	–	–	–
per 1 mol of Zinc iodide	–	–	–	–
per 1 mol of Magnesium hydroxide	–	–	–	–
per 1 mol of Magnesium iodide	–	–	–	–
per 1 mol of Zinc hydroxide	–	–	–	–

Thermodynamic data of reactants

Chemical formula	Standard enthalpy of formation Δ_fH° kJ · mol⁻¹	Standard Gibbs energy of formation Δ_fG° kJ · mol⁻¹	Standard molar entropy S° J · K⁻¹ · mol⁻¹	Standard molar heat capacity at constant pressure C_p° J · K⁻¹ · mol⁻¹
ZnI₂ (cr)	-208.03^[1]	-208.95^[1]	161.1^[1]	–
ZnI₂ (ai)	-264.26^[1]	-250.20^[1]	110.5^[1]	-238^[1]
ZnI₂ (ao)	–	-240.6^[1]	–	–
Mg(OH)₂ (cr)	-924.54^[1]	-833.51^[1]	63.18^[1]	77.03^[1]
Mg(OH)₂ (am) precipitated	-920.5^[1]	–	–	–
Mg(OH)₂ (g)	-561^[1]	–	–	–
Mg(OH)₂ (ai)	-926.84^[1]	-769.4^[1]	-159.4^[1]	–

* (cr):Crystalline solid, (ai):Ionized aqueous solution, (ao):Un-ionized aqueous solution, (am):Amorphous solid, (g):Gas

Thermodynamic data of products

Chemical formula	Standard enthalpy of formation Δ_fH° kJ · mol⁻¹	Standard Gibbs energy of formation Δ_fG° kJ · mol⁻¹	Standard molar entropy S° J · K⁻¹ · mol⁻¹	Standard molar heat capacity at constant pressure C_p° J · K⁻¹ · mol⁻¹
MgI₂ (cr)	-364.0^[1]	-358.2^[1]	129.7^[1]	–
MgI₂ (g)	-172^[1]	–	–	–
MgI₂ (ai)	-577.22^[1]	-558.1^[1]	84.5^[1]	–
Zn(OH)₂ (cr) γ	–	-553.81^[1]	–	–
Zn(OH)₂ (cr) β	-641.91^[1]	-553.52^[1]	81.2^[1]	–
Zn(OH)₂ (cr) ε	-643.25^[1]	-555.07^[1]	81.6^[1]	72.4^[1]
Zn(OH)₂ (cr) precipitated	-642.2^[1]	–	–	–
Zn(OH)₂ (ai)	-613.88^[1]	-461.56^[1]	-133.5^[1]	-251^[1]
Zn(OH)₂ (ao)	–	-522.73^[1]	–	–

* (cr):Crystalline solid, (g):Gas, (ai):Ionized aqueous solution, (ao):Un-ionized aqueous solution

References

List of references

1
Janiel J. Reed (1989)
The NBS Tables of Chemical Thermodynamic Properties: Selected Values for Inorganic and C1 and C2 Organic Substances in SI Units
https://doi.org/10.18434/M32124
National Institute of Standards and Technology (NIST)
Citation list

Δ_rG	130.5 kJ/mol
K	0.14 × 10⁻²²
pK	22.86

Δ_rG	130.7 kJ/mol
K	0.13 × 10⁻²²
pK	22.90

Δ_rG	129.2 kJ/mol
K	0.23 × 10⁻²²
pK	22.63

Δ_rG	2.9 kJ/mol
K	0.31 × 10⁰
pK	0.51

ZnI2 + Mg(OH)2 → MgI2 + Zn(OH)2